[PATCH 3/3] blk-wbt: doc: Update the doc of the wbt_lat_usec interface

[Tang Yizhou]

From: Tang Yizhou <yizhou.tang@xxxxxxxxxx>

The symbol wb_window_usec cannot be found. Update the doc to reflect the
latest implementation, in other words, the cur_win_nsec member of struct
rq_wb.

Signed-off-by: Tang Yizhou <yizhou.tang@xxxxxxxxxx>
---
 Documentation/ABI/stable/sysfs-block | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block
index 4ba771b56b3b..7bb4dce73eca 100644
--- a/Documentation/ABI/stable/sysfs-block
+++ b/Documentation/ABI/stable/sysfs-block
@@ -731,11 +731,11 @@ Contact:	linux-block@xxxxxxxxxxxxxxx
 Description:
 		[RW] If the device is registered for writeback throttling, then
 		this file shows the target minimum read latency. If this latency
-		is exceeded in a given window of time (see wb_window_usec), then
-		the writeback throttling will start scaling back writes. Writing
-		a value of '0' to this file disables the feature. Writing a
-		value of '-1' to this file resets the value to the default
-		setting.
+		is exceeded in a given window of time (see the cur_win_nsec
+		member of struct rq_wb), then the writeback throttling will
+		start scaling back writes. Writing a value of '0' to this file
+		disables the feature. Writing a value of '-1' to this file
+		resets the value to the default setting.
 
 
 What:		/sys/block/<disk>/queue/write_cache
-- 
2.25.1